Coronavirus Boats Ridde
Hint:
A Rickety Bridge Riddle
Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?
Hint:
17 mins.
The initial solution most people will think of is to use the fastest person as an usher to guide everyone across. How long would that take? 10 + 1 + 7 + 1 + 2 = 21 mins. Is that it? No. That would make this question too simple even as a warm up question.
Let's brainstorm a little further. To reduce the amount of time, we should find a way for 10 and 7 to go together. If they cross together, then we need one of them to come back to get the others. That would not be ideal. How do we get around that? Maybe we can have 1 waiting on the other side to bring the torch back. Ahaa, we are getting closer. The fastest way to get 1 across and be back is to use 2 to usher 1 across. So let's put all this together.
1 and 2 go cross
2 comes back
7 and 10 go across
1 comes back
1 and 2 go across (done)
Total time = 2 + 2 + 10 + 1 + 2 = 17 mins Did you answer this riddle correctly?
YES NO
The initial solution most people will think of is to use the fastest person as an usher to guide everyone across. How long would that take? 10 + 1 + 7 + 1 + 2 = 21 mins. Is that it? No. That would make this question too simple even as a warm up question.
Let's brainstorm a little further. To reduce the amount of time, we should find a way for 10 and 7 to go together. If they cross together, then we need one of them to come back to get the others. That would not be ideal. How do we get around that? Maybe we can have 1 waiting on the other side to bring the torch back. Ahaa, we are getting closer. The fastest way to get 1 across and be back is to use 2 to usher 1 across. So let's put all this together.
1 and 2 go cross
2 comes back
7 and 10 go across
1 comes back
1 and 2 go across (done)
Total time = 2 + 2 + 10 + 1 + 2 = 17 mins Did you answer this riddle correctly?
YES NO
A Walk In The Desert Riddle
Four men walk into the desert. Suddenly all four are simultaneously knocked out. They awake buried to their heads in the sand unable to look anywhere but straight ahead. They are positioned so that each man sees another's head before him. However between the first and second man there is a separating wall.
So the first man sees only desert. The second man sees only wall. The third man sees another's head and a wall. The fourth man sees two heads and a wall. On top of each mans head is a hat. The underside of each cap is black, but the outside of each cap is either blue or white. Before any of the men can speak, their captors tell them if they speak, they die. However, if any of them can guess the color of their cap on the first try they go free. The captors tell them that there are two blue caps and two white caps.
Being an omniscient observer of the situation, we know that the order of the caps are: blue, white, blue, white. So knowing the perspective of each man in the sand, and that they can only see the color of caps/wall/desert in front of them, which of the four men knows for certain the color of his own cap. More importantly: why?
So the first man sees only desert. The second man sees only wall. The third man sees another's head and a wall. The fourth man sees two heads and a wall. On top of each mans head is a hat. The underside of each cap is black, but the outside of each cap is either blue or white. Before any of the men can speak, their captors tell them if they speak, they die. However, if any of them can guess the color of their cap on the first try they go free. The captors tell them that there are two blue caps and two white caps.
Being an omniscient observer of the situation, we know that the order of the caps are: blue, white, blue, white. So knowing the perspective of each man in the sand, and that they can only see the color of caps/wall/desert in front of them, which of the four men knows for certain the color of his own cap. More importantly: why?
Hint:
The third man. This is because he knows there are only two of each color cap. If the man behind him (the fourth man) saw two caps that were the same color in front of him, he would know that his own must be the opposite. However, because the caps alternate in color. The fourth man has only a 50% chance of getting his hat color correct, so therefore he stays quiet. The third man realizes that the fourth man is quiet because he must not see two caps of the same color in front of him, otherwise the fourth man would say the opposite of the caps in front of him. Therefore, the third man presumes his own cap must be the opposite of the mans in front of him, and his presumption is correct. Under this same logic, after the third man speaks his color hat, the second man, even though he sees only wall, would be the next to go free, because he knows his cap must be the opposite of whichever color the third mans cap was. Did you answer this riddle correctly?
YES NO
YES NO
Single Ship Riddle
Hint:
Walking In The Rain
Samuel was out for a walk when it started to rain. He did not have an umbrella and he wasn't wearing a hat. His clothes were soaked, yet not a single hair on his head got wet. How could this happen?
Hint:
A Man Was Outside Taking A Walk When It Began To Rain
A man was outside taking a walk when it began to rain. He did not have an umbrella and he wasn't wearing a hat. His clothes were soaked, yet not a single hair on his head got wet. How could this happen?
Hint:
Three Men On A Boat
Hint: They have to use the boat.
They throw one cigarette overboard and made the boat a cigarette lighter. Did you answer this riddle correctly?
YES NO
YES NO
Roots That Nobody Sees
Hint:
One of Gollums riddles for Bilbo. The answer is mountain. Did you answer this riddle correctly?
YES NO
YES NO
Walking On Four Legs
Hint:
A Human. As an infant, a man crawls on 4 legs; as an adult he walks on two legs and as an elderly citizen he walks with a cane hence the three legs. Did you answer this riddle correctly?
YES NO
YES NO
I Sit On A Bridge
Hint:
Sunglasses. They sit on the bridge of your nose, you look through it but other people wonder what I hide. Did you answer this riddle correctly?
YES NO
YES NO
A Walk In The Rain Riddle
A man went for a walk. It started raining. The man didn't have a hat, or coat or umbrella. He got all wet - his clothes, shoes etc. Still his hair didn't get wet. How come?
Hint:
Albatross Boat Riddle
Two men walk into a restaurant by the sea and sit at the bar. Both men are covered in water. Both men order a plate of Albatross and take one bite. After chewing and swallowing, the first man stands up, walks outside, and shoots himself, while the other finishes his meal.
Hint:
The two men were stranded out in the ocean with a third man when they were beginning to stave. When an albatross landed on their life boat and died they finally had food but it was not enough to feed all three of them. They drew straws and the looser was killed and eaten. They mixed up the human meat and the albatross meat so neither person would know what they were eating. After being rescued, the friends went to eat real Albatross and the man who killed himself realized that he was the one that ate his friend. Did you answer this riddle correctly?
YES NO
YES NO
A Goat, A Wolf, And A Head Of Cabbage
A man has a goat, a wolf, and a head of cabbage. He comes to a river that has no bridge, but a small boat to cross the river. The boat can hold only one of the three things he has. If he takes over the wolf first, the goat will eat the cabbage. If he take over the cabbage first, the wolf will eat the goat.
How does he solve the problem?
How does he solve the problem?
Hint:
First, he takes over the goat. Then, he takes over the cabbage, but takes the goat back. Then, he takes over the wolf. Finally, he takes over the goat again. Did you answer this riddle correctly?
YES NO
YES NO
Soldiers Across A River
A detachment of soldiers must cross a river. The bridge is broken, the river is deep. What to do?
Suddenly the officer in charge spots two boys playing in a row boat by the shore.
The boat is so tiny however, that is could only hold two boys or one soldier.
Still all the soldiers make it across the river in the boat. How?
Suddenly the officer in charge spots two boys playing in a row boat by the shore.
The boat is so tiny however, that is could only hold two boys or one soldier.
Still all the soldiers make it across the river in the boat. How?
Hint:
First the boys cross the river and 1 boy comes back and gets a soldier and keeps going back until all the soldiers have made it across safely. Did you answer this riddle correctly?
YES NO
YES NO
Two Chemistry Students Walk Into A Bar
Two chemistry students walk into a bar.
The first says, "I'll order an H2O."
The second then says, "I'll order an H2O too."
Why did the second student die?
The first says, "I'll order an H2O."
The second then says, "I'll order an H2O too."
Why did the second student die?
Hint:
"H2O too" sounds like "H2O2", which is hydrogen peroxide. Hydrogen peroxide is a poison and can be deadly if its concentration in water is sufficiently high. Did you answer this riddle correctly?
YES NO
YES NO
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